JP2003335143A - Active four-wheel drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a four-wheel drive device offering simple construction permitting highly precise and active control of the transmission distribution of driving force transmitted from an engine to a driving wheel side and a driven wheel side. <P>SOLUTION: The driving force of the engine is input to a driving gear and distributed to right and left wheels on the driving wheel side by a driving wheel side differential gear. A driving wheel side propeller shaft is rotated by engagement between the driving gear and a speed increasing gear and the rotation of the driving wheel side propeller shaft is transmitted to a driven wheel side propeller shaft by a differential mechanism. The rotation of the driven wheel side propeller shaft is input to a driven wheel side differential gear by engagement between a speed reducing gear and the driven gear and distributed to right and left wheels on the driven wheel side. A differential control element of the differential mechanism is rotation controlled by a motor to give relative differential rotation to the driving wheel side propeller shaft and the driven wheel side propeller shaft. Thus, the driving force of the engine is selectively distributed to the driving wheel side and the driven wheel side. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-wheel drive system for controlling distribution of driving force to a main driving wheel side and a driven wheel side.

[0002]

2. Description of the Related Art A carrier is provided with a planetary gear which is connected to a main shaft side and a driven shaft side of a propeller shaft and simultaneously meshes with two internal gears on coaxial lines having slightly different numbers of teeth. Japanese Patent No. 2643979 discloses a four-wheel drive device that controls the relative rotation of the front and rear wheel side output shafts by controlling the rotation of an electric motor to control the transmission distribution of the driving force to the front wheel side and the rear wheel side. It is described in the official gazette.

[0003]

In the above-mentioned conventional device,
Since a complicated differential mechanism is used, there are problems in cost and reliability.

The present invention has been made in order to solve the above-mentioned conventional inconvenience, and the transmission distribution of the driving force transmitted from the engine to the main driving wheel side and the driven wheel side has a simple structure and an appropriate gear ratio setting. Is to provide a four-wheel drive device that can be actively controlled with high precision.

[0005]

In order to solve the above-mentioned problems, the structural feature of the present invention as set forth in claim 1 is that the driving force from the engine is input to the drive gear to the left and right wheels on the main driving wheel side. Main-wheel-side differential gear to be distributed, main-wheel-side propulsion shaft having a speed increasing gear meshing with the drive gear, and driven-wheel-side differential to distribute the power input to the driven gear to the driven-wheel-side left and right wheels. A differential gear and a driven wheel side propulsion shaft having a reduction gear that meshes with the driven gear are provided, and first and second differential elements and a differential control element of a differential mechanism are provided on the main drive wheel side propulsion shaft, The driven wheel-side propulsion shaft and the output shaft of the electric motor are respectively connected to each other, the rotational speed ratio between the speed increasing gear and the drive gear, the second differential element and the first differential element when the differential control element is stationary. Multiplied by the rotation speed ratio between the driven gear and the reduction gear. Is that was set to be approximately 1.

According to a second aspect of the present invention, in the active four-wheel drive system according to the first aspect, the differential mechanism is a planetary gear, and the carrier of the planetary gear is connected to the main drive wheel side propulsion shaft. The ring gear is connected to the driven wheel-side propulsion shaft, and the sun gear is connected to the electric motor.

According to a third aspect of the present invention, in the active four-wheel drive system according to the first or second aspect, a drive circuit for rotationally driving the electric motor as a motor and a regenerative control circuit for operating as a generator. And a control means for connecting the electric motor to a drive circuit or a regeneration control circuit.

According to a fourth aspect of the present invention, there is provided an active four-wheel drive device according to any one of the first to third aspects, wherein the electric motor and the differential control element of the differential mechanism are arranged between the electric motor and the differential control element. In addition, a clutch for engaging and disengaging the power transmission between the two is interposed.

According to a fifth aspect of the present invention, there is provided a characteristic yaw rate setting means for obtaining a target yaw rate from a steering angle and a vehicle speed in the active four-wheel drive system according to any one of the first to fourth aspects. And a yaw rate measuring means for actually measuring or measuring the yaw rate, and for driving the electric motor in the normal and reverse directions according to the difference between the target yaw rate and the actually measured or measured yaw rate.

[0010]

In the invention according to claim 1 configured as described above, the driving force from the engine is input to the drive gear and distributed to the left and right wheels on the main driving wheel side by the main driving wheel side differential gear. The main drive wheel side propulsion shaft is rotated by the engagement of the drive gear and the speed increasing gear, the rotation of the main drive wheel side propulsion shaft is transmitted to the driven wheel side propulsion shaft by the differential mechanism, and the rotation of the driven wheel side propulsion shaft is It is input to the driven wheel side differential gear by meshing of the reduction gear and the driven gear and distributed to the left and right wheels on the driven wheel side. The differential control element of the differential mechanism is rotationally controlled by the electric motor, so that the main driving wheel-side propulsion shaft connected to the first differential element and the driven wheel-side propulsion shaft connected to the second differential element are separated from each other. It is differentially rotated relatively. As a result, the driving force of the engine can be arbitrarily distributed to the main driving wheel side and the driven wheel side. Further, the rotational speed ratio between the speed increasing gear and the drive gear, the rotational speed ratio between the second differential element and the first differential element when the differential control element is stationary, and the rotational speed ratio between the driven gear and the reduction gear. Since the gear ratio is such that the product obtained by multiplying by is approximately 1,
When the main driving wheel side and the driven wheel side are rotationally driven at the same rotational speed, the differential control element of the differential mechanism and thus the electric motor are maintained in a stationary state.

In the invention according to claim 2 configured as described above, the carrier and the ring gear of the planetary gear are connected to the main driving wheel side driving shaft and the driven wheel side driving shaft as the first and second differential elements, and the sun gear is connected. Since the differential control element is connected to the electric motor, the transmission distribution of the driving force to the driving wheel side and the driven wheel side can be controlled with high precision with a simple configuration.

In the invention according to claim 3 configured as described above, the electric motor functions as a generator by being connected to the regenerative control circuit, and the difference in rotation speed between the first and second differential elements is A torque is generated by rotating at a corresponding rotation speed. As a result, it is possible to transmit the driving force corresponding to the difference in rotation speed between the main driving wheel side and the driven wheel side to the driven wheel side. At this time, by controlling the energy recovery rate of the generator, it is possible to change the characteristics of the generated torque with respect to the rotation speed of the motor and control the transmission of the driving force to the driven wheel side in a multidimensional manner. It is also possible to charge the battery with electric energy generated by an electric motor that functions as a generator.

In the invention according to claim 4 configured as described above, when the left and right wheels, which are either the main driving wheel side or the driven wheel, are lifted and pulled when a failure occurs, differential control of the electric motor and the differential mechanism is performed. Power transmission to and from the elements can be disengaged by disengaging the clutch, thus preventing the electric motor from rotating at high speed.

In the invention according to claim 5 configured as described above, when the difference between the target yaw rate and the actual yaw rate is a negative value and understeering is performed, the distribution of the driving force to the rear wheels is increased, When the difference is a positive value and over-steering, the distribution of the driving force to the front wheels is increased, so that the actual deflection ratio of the vehicle can be appropriately controlled according to the steering angle and the vehicle speed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where the active four-wheel drive system according to the first embodiment of the present invention is applied to an FF vehicle will be described below. In FIG. 1, the driving force of the engine 10 is the transmission 1
The rotation is transmitted to the drive gear 13, which is a ring gear of the main drive wheel side differential gear 12, via 1. The main driving wheel side differential gear 12 distributes the driving force to the left and right front wheels Tfr, Tfl, which are the main driving wheels in an FF vehicle. The drive gear 13 meshes with the speed increasing gear 14 fixed to the tip of the main driving wheel side propulsion shaft 15 to form a transfer speed increasing mechanism, and the rear end of the main driving wheel side propulsion shaft 15 has a first difference of the differential mechanism 16. It is connected to the moving element 17. The second differential element 18 of the differential mechanism 16 is connected to the driven wheel-side propulsion shaft 19, and the first and second differential elements 17, 1 are connected.
The differential control element 20 for controlling the differential of 8 is an electric motor 21
It is designed to rotate forward and backward. That is, the carrier 17 supporting the planetary gear 22 of the planetary gear 16 which is a differential mechanism serves as the first differential element and serves as the main drive wheel side propulsion shaft 15
A ring gear 18 connected to the rear end of the electric gear 21 and a ring gear 18 meshing with the planetary gear 22 are connected to the driven wheel side propulsion shaft 19 as a second differential element, and a sun gear 20 meshing with the planetary gear 22 of the electric motor 21 as a differential control element. Gears 23 and 24 are rotatably connected to the output shaft. To further amplify the torque of the electric motor 21, a reduction gear may be added between the gears 23 and 24 as needed.

The reduction gear 25 fixed to the rear end of the driven wheel-side propulsion shaft 19 meshes with the driven gear 27 which is a ring gear of the driven wheel-side differential gear 26 to form a rear differential reduction mechanism. Driven wheel side differential gear 2
6 distributes the driving force to the left and right rear wheels Trr and Trl which are the driven wheels. The rotational speed ratio between the speed increasing gear 14 and the drive gear 13 is r1, the rotational speed ratio between the ring gear 18 and the carrier 17 when the sun gear 20 is stationary is r2, and the rotational speed ratio between the driven gear 27 and the reduction gear 25 is r3. Then, the gear ratios are set so that the product of r1, r2, and r3 becomes approximately 1, and the sun gear 20 hardly rotates unless the motor 21 is driven when the vehicle travels straight. . In the planetary gear 16, if the numbers of teeth of the ring gear 18 and the sun gear 20 are Zr and Zs, the rotation speed ratio r2 between the ring gear 18 and the carrier 17 when the sun gear 20 is stationary is (1 + Zs / Zr).
Becomes Since the rotational speed ratio between the ring gear 18 and the carrier 17 can be made relatively close to 1 at 1.4 or less, the conventional transfer speed increasing mechanism and the rear differential speed reducing mechanism can be used as they are. Further, since the rotation speed of the reduction gear 25 is increased, the torque applied to the reduction gear 25 is reduced, which is advantageous in terms of strength.

Next, the operation of the first embodiment will be described. The rotation from the engine 10 rotationally drives the drive gear 13 via the transmission 11, and is distributed to the left and right by the main driving wheel side differential gear 12 to rotationally drive the left and right front wheels Tfr, Tfl which are the main driving wheels. The main drive wheel side propulsion shaft 15 is rotated by the engagement of the drive gear 13 and the speed increasing gear 14, and the carrier 17 of the planetary gear 16 is rotationally driven. The ring gear 18 is rotationally driven with its speed increased by the rotational speed ratio between the ring gear 18 and the carrier 17. Ring gear 18
The driven wheel side propulsion shaft 19 is rotated by the rotation of the driven wheel 27, the driven gear 27 of the driven wheel side differential gear 26 that meshes with the reduction gear 25 is rotationally driven, and the left and right rear wheels Tr that are the driven wheels are driven.
The r and Trl are driven to rotate.

For the sake of simplicity, it is assumed that the vehicle runs straight and the conditions such as the load applied to the front wheel side and the rear wheel side are the same. When the rotation of the electric motor 21 is restricted and the sun gear 20 is stationary, the rotation speed ratio r1 between the speed increasing gear 14 and the drive gear 13, the ring gear 18 and the carrier 17
The product of the rotational speed ratio (1 + Zs / Zr) and the rotational speed ratio r3 of the driven gear 27 and the reduction gear 25 is approximately 1.
The front wheels Tfr, Tfl and the rear wheels Trr, Trl are rotationally driven at the same rotation speed, and the driving force from the engine 10 is evenly distributed to the main driving wheel side and the driven wheel side. The output shaft of the motor 21 is the sun gear 2
Since it is connected to 0 by gears 23 and 24 after being greatly decelerated, it is possible to receive the reaction force acting on the sun gear 20 by the static torque of the output shaft of the motor 21.

The front wheels Tfr and Tfl on the main driving wheel side are the transmission 11
The front wheels Tfr, Tf are rotated by Nf rpm by
When the driving force is distributed more to the rear wheels Trr and Trl than the rear wheels, the motor 21 is properly rotated in the normal direction at a low speed Arpm. Due to the normal rotation of the sun gear 20, the rotation speed of the ring gear 18, that is, the driven wheel-side propulsion shaft 19 is {Nf × r1 × (1 + Zs / Zr) −A.
× Zs / Zr} rpm, and the rotation speed of the rear wheels Trr, Trl on the driven wheel side becomes Nf-A × r3 × Zs / Zrrpm, and the front wheels Tfr, T
Axr3xZs / Zrrpm less than fl. This allows
The slip ratios of the rear wheels Trr and Trl with respect to the road surface are the front wheels Tfr and Tfl.
Less, driving power from the engine is less than front wheels Tfr, Tfl
Is distributed more than the rear wheels Trr and Trl by a desired ratio.

On the contrary, when the driving force is distributed to the rear wheels Trr, Trl more than the front wheels Tfr, Tfl, the motor 21 is appropriately rotated at a low speed.
When reversing at Arpm, the rotation speed of the driven wheel side propulsion shaft 19 becomes
{Nf × r1 × (1 + Zs / Zr) + A × Zs / Zr} rpm, the rear wheel Trr and Trl rotation speed becomes Nf + A × r3 × Zs / Zrrpm, and Axr3 × Zs from the front wheel Tfr and Tfl / Zrrpm increases.
As a result, the slip ratio of the rear wheels Trr, Trl with respect to the road surface becomes larger than that of the front wheels Tfr, Tfl, and the driving force from the engine is distributed to the rear wheels Trr, Trl more than the front wheels Tfr, Tfl by a desired ratio.

When the motor 21 is allowed to rotate freely,
Since the sun gear 20 does not receive the reaction force, the power transmission path from the main driving wheel side propulsion shaft 15 to the driven wheel side propulsion shaft 19 is cut off, the rear wheels Trr and Trl roll on the road surface, and all the driving force is applied to the front wheels. It is distributed to Tfr and Tfl. However, in this case as well, the rear wheel Tr
Since the rotational speeds of r, Trl and the front wheels Tfr, Tfl are substantially equal, the motor 21 hardly rotates.

In the second embodiment, as shown in FIG.
The differential gear 30 is used as a differential mechanism. That is, the side gear 3 of the differential gear 30
1, 32 are connected to the driving wheel side and driven wheel side propulsion shafts 15 and 19, and the output shaft of the motor 21 is rotationally connected to the ring gear 33 by gears. In this case, since the driven wheel-side propulsion shaft 19 rotates in the reverse direction with respect to the rotation direction of the main driving-wheel-side propulsion shaft 15, the reduction gear 25 and the driven gear 27 are arranged left and right as in the case of the first embodiment. The rear wheels are rotationally driven in the forward direction. Further, since the main wheels and the driven wheels 15 and 19 have the same rotation speed, the rotation speed ratio r1 between the speed increasing gear 14 and the drive gear 13 and the rotation speed between the driven gear 27 and the reduction gear 25 are increased. The product of the ratio r3 is approximately 1.

In the third embodiment, as shown in FIG.
The main driving wheel side propulsion shaft 15 is connected to the sun gear 20 of the planetary gear 16 as a differential mechanism, the driven wheel side propulsion shaft 19 is connected to the carrier 17, and the motor 21 is connected to the ring gear 18.
The output shaft of is rotatably connected by a gear. As shown in FIG. 4, a drive / regeneration control system 35 connected to a battery 34 is connected to the motor 21, and the drive / regeneration control system 35 includes a drive circuit 36 for rotationally driving the electric motor 21 as a motor and a generator. A regenerative control circuit 37 that operates as described above and a control unit 38 that connects the motor 21 to the drive circuit 36 or the regenerative control circuit 37 are provided. Figure 5
The inverter 39 shown in FIG.
When it is connected to No. 1 and is controlled to the driving side by the control means 38, it functions as the driving circuit 36, and when controlled to the braking side, it functions as the regenerative control circuit 37.

In the case of the third embodiment, when the rotation of the motor 21 is restricted and the ring gear 18 is stationary, the rotation speed ratio r1 between the speed increasing gear 14 and the driving gear 13 is the carrier when the ring gear 18 is stationary. The product obtained by multiplying the rotational speed ratio Zs / (Zs + Zr) of 17 and the sun gear 20 and the rotational speed ratio r3 of the driven gear 27 and the reduction gear 25 is approximately 1, so that the front wheels Tfr, T
The fl and the rear wheels Trr, Trl are rotationally driven at the same rotation speed, and the driving force from the engine 10 is evenly distributed to the main driving wheel side and the driven wheel side. Since the output shaft of the motor 21 is connected to the ring gear 18 by being greatly decelerated by the gears 23 and 24, it is possible to generate a static torque that resists the reaction force received by the ring gear 18.

The motor control program shown in FIG. 6 is executed by the electronic control unit (ECU) as the control means 38 at predetermined time intervals, and the distribution ratio of the driving force transmitted to the front wheels Tfr, Tfl and the rear wheels Trr, Trl is calculated. It is determined whether or not the mode is the active control mode (steps 41 and 42), and when the active control is performed, the inverter 39 is controlled to the drive side and the drive circuit 3 is controlled.
6 (step 43), the electronic control unit (EC
When a large amount is distributed to the front wheels based on the command from U), the electric motor 21 is reversely rotated, and when a large amount is distributed to the rear wheels, the electric motor 21 is normally rotated.

In the differential limiting mode in which the driving force transmitted to the driven wheels is controlled according to the differential state between the main driving wheel side and the driven wheel side, the inverter 39 is controlled to the braking side and the regenerative control circuit 37 is provided. When the motor 21 is rotated based on the rotation difference between the front wheels Tfr, Tfl and the rear wheels Trr, Trl, the motor 21 operates as a generator to generate power and generate torque in proportion to the rotation speed. Therefore, it operates as a four-wheel drive device that transmits the driving force to the rear wheels Trr and Trl according to the rotation difference between the front and rear wheels. At this time, the electronic control unit (EC
By controlling the inverter 39 with U) to control the energy recovery rate of the generator, as shown in FIG. 7, the increasing rate of the generated torque with respect to the increasing number of rotations of the motor 21 is changed to the rear wheels Trr, Trl. It is possible to control the transmission of the driving force in a multidimensional manner in a high dimension. The motor 2
When the increasing rate of the generated torque with respect to the increase of the rotational speed of 1 is increased, the ratio of the driving force distributed to the rear wheels with respect to the rotational speed difference between the front and rear wheels is increased. When the generated torque is set to zero, the driving force is not transmitted to the rear wheels Trr and Trl.

In the differential limiting mode in which the driving force transmitted to the driven wheels is controlled in accordance with the differential state between the main driving wheel side and the driven wheel side, the regenerative control circuit 37 controls the inverter 39 to the braking side. Instead of functioning as, the converter may be connected to the motor 21 as the regeneration control circuit 37. As a result, in the limited differential mode, the motor 21 is connected to the converter, and when the motor 21 is rotated based on the rotation difference between the front wheels Tfr, Tfl and the rear wheels Trr, Trl, the electric energy generated by the generator is generated. The battery 34 is charged. In this case as well, by controlling the converter with the electronic control unit (ECU) to control the energy recovery rate of the generator, the characteristics of the generated torque with respect to the rotational speed of the motor 21 are changed to drive the rear wheels Trr, Trl. The transmission of can be controlled. As shown in FIG. 7, when the increase rate of the generated torque with respect to the increase of the rotation speed of the motor 21 is increased, the energy recovery rate to the battery 34 is increased, and the rear wheels are subjected to the difference in the rotation speed of the front and rear wheels. The proportion of the driving force distributed is increased.

In the fourth embodiment, as shown in FIG.
A pair of pinions 52, 5 meshing with each other on the carrier 51
3 is rotatably supported, one pinion 52 is meshed with a sun gear 54, the other pinion 53 is meshed with a ring gear 55, and a double planetary gear 50 is used as a differential mechanism, and a main drive wheel side propulsion shaft 15 is connected to a carrier 51. , Sun Gear 5
4 the bevel gear 5 connected to the driven wheel side propulsion shaft 19 and detachably connected to the ring gear 55 via the clutch 56.
7, a bevel gear 58 fixed to the output shaft of the motor 21 is meshed. When the rotation of the motor 21 is restricted and the ring gear 55 is stationary, the rotation speed ratio r1 between the speed increasing gear 14 and the drive gear 13, the rotation speed ratio between the sun gear 52 and the carrier 51 (1-Zr / Zs), Since the product obtained by multiplying the rotational speed ratio r3 between the driven gear 27 and the reduction gear 25 is about 1, the left and right front wheels Tfr, Tfl and the left and right rear wheels Trr, Trl are rotationally driven at the same rotational speed, and the engine 10 The driving force is evenly distributed to the main driving wheel side and the driven wheel side. In this case, the driven wheel-side propulsion shaft 19
Is reversely rotated with respect to the rotation direction of the main driving wheel side propulsion shaft 15, the reduction gear 25 and the driven gear 27 are arranged left and right as in the case of the first embodiment, and the rear wheels are rotationally driven in the forward direction. It has become so. If Zs / Zr is halved,
The rotation speed ratio between the sun gear 52 and the carrier 51 is -1. Since the output shaft of the motor 21 is connected to the ring gear 53 by being greatly decelerated by the bevel gears 57 and 58, it is possible to generate a stationary torque that resists the reaction force received by the ring gear 53.

With this configuration, when the left and right front wheels Tfr, Tfl on the main driving wheel side are lifted and towed at the time of failure, the clutch 56 is disengaged and the motor 21 and the ring gear 5 are pulled.
Since the power transmission to and from the motor 5 can be cut off, the motor 21 does not rotate at high speed during towing. The clutch 56 may be interposed between the output shaft of the motor 21 and the bevel gear 58.

In the fifth embodiment, as shown in FIG.
In the first embodiment, the target yaw rate is calculated from the steering angle and the vehicle speed.
A target yaw rate setting means 60 for obtaining Yt and a yaw rate sensor 61 for actually measuring the actual yaw rate Yr are provided, and the motor 21 is driven in the forward or reverse direction according to the difference (Yr-Yt) between the target yaw rate Yt and the actually measured yaw rate Yr. The distribution control means 62 is provided. That is, as shown in FIG. 10, a vehicle speed sensor 66, a steering angle sensor 67, a yaw rate sensor 61, a lateral acceleration sensor 68, etc. are connected to a central processing unit CPU 65 of an electronic control unit (ECU), and the vehicle speed, the steering angle, The measured value such as the yaw rate is input. An inverter 39 is connected to the CPU 65, and command values for the rotation direction and speed of the electric motor 21 are output. Note that lateral acceleration may be used as a substitute for the yaw rate.

The yaw rate control program shown in FIG. 11 is executed every predetermined time, and the vehicle speed sensor 66 and the steering angle sensor 67 are executed.
The vehicle speed and the steering angle are input from (step 71), and the target yaw rate Yt is set from the map shown in FIG. 12 based on these input values (step 72). Target yaw rate Yt
May be calculated from the formula Yt = constant K × vehicle speed × steering angle. Step 72 for setting the target yaw rate Yt constitutes the yaw rate setting means 61. The actual yaw rate Yr is input from the yaw rate sensor 61 (step 73), and it is determined whether or not the yaw rate Yr is larger than the value obtained by adding the set value α to the target yaw rate Yt (step 7).
4). When it is large and tends to oversteer, the rotation direction and speed command values of the electric motor 21 are set so as to be distributed more to the front wheels (step 75) and output to the inverter 39 (step 76), and the electric motor 2
1 is driven. This distribution control is based on the actual yaw rate Yr.
The known PiD control or the like is performed so that the value (Yr−Yt) obtained by subtracting the target yaw rate from is zero. If the yaw rate Yr is less than or equal to the target yaw rate Yt plus the set value α,
It is determined whether the yaw rate Yr is smaller than the target yaw rate Yt minus the set value α (step 77). If the steering angle is small and there is an understeering tendency, the command values of the rotation direction and speed of the electric motor 21 are set so as to distribute more to the rear wheels (step 78), and the inverter 39
(Step 76), the electric motor 21 is driven. If the yaw rate Yr is larger than the value obtained by subtracting the set value α from the target yaw rate Yt and smaller than the value obtained by adding the set value α, the current rotation direction and speed command values of the electric motor 21 are maintained (step 79). It is output to 39.

[Brief description of drawings]

FIG. 1 is a diagram showing an active four-wheel drive system according to a first embodiment.

FIG. 2 is a diagram showing an active four-wheel drive system according to a second embodiment.

FIG. 3 is a diagram showing an active four-wheel drive system according to a third embodiment.

FIG. 4 is a block diagram showing a drive / regeneration control system connected to a motor 21.

FIG. 5 is a diagram showing an invar.

FIG. 6 is a diagram showing a motor control program.

FIG. 7 is a graph showing an increase rate of generated torque with respect to an increase in motor rotation speed.

FIG. 8 is a diagram showing an active four-wheel drive system according to a fourth embodiment.

FIG. 9 is a diagram showing an active four-wheel drive system according to a fifth embodiment.

FIG. 10 is a block diagram showing a yaw rate control system.

FIG. 11 is a diagram showing a yaw rate control program.

FIG. 12 is a map for obtaining a target yaw rate from vehicle speed and steering angle.

[Explanation of symbols]

10 ... Engine, 11 ... Transmission, 12 ... Main driving wheel side differential gear, 13 ... Main driving gear, 14 ... Speed increasing gear, 1
5 ... Main drive wheel side propulsion shaft, 16 ... Planetary gear (differential mechanism), 17, 51 ... Carrier, 18, 55 ... Ring gear, 19 ... Driven wheel side propulsion shaft, 20, 54 ... Sun gear, 2
1 ... Electric motor, 23, 24 ... Gear, 25 ... Reduction gear,
26 ... driven differential gear, 27 ... driven gear, 3
0 ... Differential gear (differential mechanism), 31, 32 ...
Side gear, 33 ... Ring gear, 34 ... Battery, 35
... Drive / regeneration control system, 36 ... Drive circuit, 37 ... Regeneration control circuit, 38 ... Control means, 39 ... Inverter, 50
… Double planetary gears, 52, 53… Pinion, 56
... clutch, 57, 58 ... bevel gear, 60 ... target yaw rate setting means, 61 ... yaw rate sensor, 62 ... distribution control means.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B60K 17/356 ZYW B60K 17/356 ZYWB 25/00 25/00 C B60L 11/14 B60L 11/14 (72 ) Inventor Akihiro 1-1, Asahi-cho, Kariya city, Aichi Toyota Koki Co., Ltd. (72) Inventor Akio Matsumoto 1-1, Asahi-cho, Kariya city Aichi F-term (reference) 3D039 AA04 AB02 AB27 AC39 3D043 AA01 AA06 AB01 AB17 EA02 EA05 EA23 EA39 EA42 EE06 EE08 EE12 EF18 5H115 PA01 PC06 PG04 PI21 PI29 PO17 PU08 PU28 PV09 QN03 SE04 TE02 TE05

Claims (5)

[Claims] 1. A main drive wheel-side propulsion system having a main drive wheel-side differential gear, into which a drive force from an engine is input to a drive gear and distributed to right and left wheels on the main drive wheel side, and a speed-increasing gear meshing with the drive gear. The shaft, a driven wheel side differential gear that distributes the power input to the driven gear to the driven wheel side left and right wheels, and a driven wheel side propulsion shaft that has a reduction gear that meshes with the driven gear are provided, and a differential The first and second differential elements and the differential control element of the mechanism are connected to the main driving wheel side propulsion shaft, the driven wheel side propulsion shaft, and the output shaft of the electric motor, respectively, to rotate the speed increasing gear and the drive gear. The product obtained by multiplying the rotational speed ratio between the second differential element and the first differential element when the differential control element is stationary and the rotational speed ratio between the driven gear and the reduction gear is approximately 1
An active four-wheel drive device characterized by the following. 2. The differential mechanism is a planetary gear,
2. The active four-wheel drive system according to claim 1, wherein a carrier of the planetary gear is connected to a main driving wheel side propulsion shaft, a ring gear is connected to the driven wheel side propulsion shaft, and a sun gear is connected to the electric motor. . 3. A drive circuit for rotationally driving the electric motor as a motor, a regeneration control circuit for operating the generator as a generator, and control means for connecting the electric motor to the drive circuit or the regeneration control circuit. Item 4. The active four-wheel drive system according to Item 1 or 2. 4. A clutch for engaging and disengaging power transmission between the electric motor and the differential control element of the differential mechanism is interposed between the electric motor and the differential control element. Active four-wheel drive. 5. The active four-wheel drive system according to claim 1, further comprising a target yaw rate setting means for obtaining a target yaw rate from a steering angle and a vehicle speed, and a yaw rate measuring means for actually measuring or measuring an actual yaw rate. An active four-wheel drive device characterized in that the electric motor is driven in forward and reverse directions according to a difference between the target yaw rate and an actually measured or measured yaw rate.